One prior art auto device mounting structure comprises a sleeve-shaped bracket which is adapted to be affixed to an instrument panel or mount board of a car so as to define a recess behind an aperture of the instrument panel to receive therein an auto device such as auto radio, auto stereo, etc. which is inserted from the front side of the instrument panel. If the bracket is too short in the axial direction thereof with respect to the back and forth length of the auto device, it cannot prevent the rear half of the auto device therein fluctuating or rotating along with movement of the car, even if the bracket itself is reliably fixed to the instrument panel.
In this connection, the prior art mounting structure provides the back face of the auto device itself with a projection or a bolt to engage some adequate fixed member immovable with respect to the car.
By this fixture method, however, since the projection or bolt as well as the fixed member of the car is hidden behind the auto device upon its placement, an operator cannot readily fit the projection to the fixed member, nor tighten the bolt.